The difference between the two is known as pulse deficit. To govern the pulse deficit, one nurse sums up the heart rate over auscultation at the apex while a second nurse concurrently palpates and sums up the radial pulse for a complete. The pulse deficit arises when there are fewer pulses than there are heartbeats. The atrial fibrillation and atrial flutter can cause pulse deficit since they cause the heart to beat so fast, and often unevenly, that the strength of blood out of the heart at times not strong enough to make a pulse.
